A ball in the trough is not detected, and under the playfield the trough switch's wire actuator is hanging loose and bent.

Ball in the trough not registering: switch wire actuator dangling or bent

Cause: The wire actuator for the trough switch had come out of position and been bent out of shape.

Checks

• Look at the trough switch under the playfield with a ball in the trough and check that the wire is pressed by the ball.
• Compare with the same part on another game or a photo.

Fix

• Refit the wire with its short leg under the switch, then bend the long part so a resting ball closes the switch reliably; bend a new wire if the old one is too far gone.

Systems

• Williams System 6 / 6A

Games

• Time Warp

Related tips

• Outhole kicker sometimes fires twice after ejecting: replace the trough switch

Source: Pinball Repair help group!! (Facebook group)